IE中的org.openqa.selenium.NoSuchElementException错误，但相同的代码在Chrome和Firefox中运行良好

Question

我编写了一个登录脚本，当我使用ChromeDirver和FFDriver执行它时，它运行正常。但是当我使用IE驱动程序运行相同时，它会失败并发出以下错误。

Exception in thread "main" org.openqa.selenium.NoSuchElementException: Unable to find element with css selector == #mod\-login\-username
For documentation on this error, please visit: http://seleniumhq.org/exceptions/no_such_element.html
Build info: version: '3.12.0', revision: '7c6e0b3', time: '2018-05-08T15:15:08.936Z'
System info: host: 'LENOVO', ip: '192.168.1.101', os.name: 'Windows 10', os.arch: 'amd64', os.version: '10.0', java.version: '1.8.0_171'
Driver info: org.openqa.selenium.ie.InternetExplorerDriver
Capabilities {acceptInsecureCerts: false, browserName: internet explorer, browserVersion: 11, javascriptEnabled: true, pageLoadStrategy: normal, platform: WINDOWS, platformName: WINDOWS, proxy: Proxy(), se:ieOptions: {browserAttachTimeout: 0, elementScrollBehavior: 0, enablePersistentHover: true, ie.browserCommandLineSwitches: , ie.ensureCleanSession: false, ie.fileUploadDialogTimeout: 3000, ie.forceCreateProcessApi: false, ignoreProtectedModeSettings: false, ignoreZoomSetting: false, initialBrowserUrl: http://localhost:39714/, nativeEvents: true, requireWindowFocus: false}, setWindowRect: true, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}}
Session ID: af1a703a-0216-4c67-8c51-1292d13e399c
*** Element info: {Using=id, value=mod-login-username}
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.openqa.selenium.remote.http.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:187)
    at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:122)
    at org.openqa.selenium.remote.http.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:49)
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:158)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:83)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:543)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:317)
    at org.openqa.selenium.remote.RemoteWebDriver.findElementById(RemoteWebDriver.java:363)
    at org.openqa.selenium.By$ById.findElement(By.java:188)
    at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:309)
    at pageObjects.Admin_Login.txtbx_Username(Admin_Login.java:13)
    at testcases.testcase01.main(testcase01.java:29)

这是脚本： -

package pageObjects;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;

public class Admin_Login {

    private static WebElement element = null;

public static WebElement txtbx_Username(WebDriver driver) {

    element = driver.findElement(By.id("mod-login-username"));

    return element;
}

public static WebElement txtbx_Password (WebDriver driver) {

    element = driver.findElement(By.xpath("mod-login-password"));

    return element;
}

public static WebElement btn_Login (WebDriver driver) {

    element = driver.findElement(By.id("mod-login-password"));

    return element;
}
}

我不明白为什么脚本显示错误“无法找到带有css选择器的元素......”因为我只使用id来查找元素而不是CSS选择器。任何人都可以提出建议。

Answer 1

此错误消息......

Exception in thread "main" org.openqa.selenium.NoSuchElementException: Unable to find element with css selector == #mod\-login\-username 

...暗示 InternetExplorerDriver 无法根据您使用的定位器策略找到任何元素。

原因

正如您所提到的，相同的代码使用ChromeDirver / Chrome和GeckoDriver / Firefox，值得一提的是，不同的浏览器引擎以不同的方式呈现HTML DOM。因此，脆弱的定位策略可能无法在所有浏览器中使用。

根据您的问题，script showing the error of "Unable to find element with css selector ..." as I have only used id根据 WebDriver W3C编辑草案再次值得一提的是，首选的Locator Strategies入伍者如下：

• "css selector" ：CSS选择器
• "link text" ：链接文字选择器
• "partial link text" ：部分链接文字选择器
• "tag name" ：标记名称
• "xpath" ：XPath选择器

快照：

通过相应的客户端特定绑定传播更改。对于 Selenium-Java 客户，client code内部基于 id 的定位策略， name 通过switchcase 内部转换到等效的 css选择器，如下所示：

        switch (using) {
          case "class name":
            toReturn.put("using", "css selector");
            toReturn.put("value", "." + cssEscape(value));
            break;

          case "id":
            toReturn.put("using", "css selector");
            toReturn.put("value", "#" + cssEscape(value));
            break;

          case "link text":
            // Do nothing
            break;

          case "name":
            toReturn.put("using", "css selector");
            toReturn.put("value", "*[name='" + value + "']");
            break;

          case "partial link text":
            // Do nothing
            break;

          case "tag name":
            toReturn.put("using", "css selector");
            toReturn.put("value", cssEscape(value));
            break;

          case "xpath":
            // Do nothing
            break;
        }
        return toReturn;

快照：

因此，尽管你提供：

(By.id("mod-login-username"))

错误显示：

Unable to find element with css selector == #mod\-login\-username